There are 2 symptoms that are always present with the swine flu that you don't get with allergies.

While allergies can make you feel like crap, allergies do not cause fever. Without fever, you don't have the swine flu. Another symptom that almost everyone with the flu will have is body aches. This is also very unusual with seasonal allergies or allergies to dogs or cats.

A runny nose and congested sinuses, even if combined with coughing, are not signs of swine flu. If these are your symptoms, you likely have either allergies or possibly a sinus infection. Not so pleasant either, but certainly not swine flu.